Improved Ion Beam Sources

Abstract

A UK-based university spin-out has developed a way of increasing and independently controlling the thrust density and specific impulse (exhaust velocity) of a gridded ion engine (GIE) for space propulsion.

Description

A method of increasing and indepedently controlling the thrust density and specific impulse (exhaust velocity) of a gridded ion engine (GIE) for space propulsion has been developed. In addition the beam divergence can be reduced by about a factor of 6 times compared to a conventional GIE. This new type of device should be applicable to future high power (circa 25 kW and above) thrusters and high specific impulse (>~ 6000s) used for future outer planet and lunar/Mars infrastructure and sample return missions. We have investigated the lifetime and found it to be as good if not better than conventional GIEs.

This technology could be applicable to ground based applications of ion beams including surface modifications i.e. improved surface properties such as wear or hardness or texturing or deposition systems. The improved ion sources could be more compact (smaller diameter) allowing the overall vacuum chamber to be smaller and would have the advantage of being able to deliver the same overall current in a smaller diameter source (higher current density) or alternatively higher current densities for the same size of source; the capability of independent control of ion energy and current density in the same source (without any design and mechanical modifications) is a unique feature. In addition, a lower beam divergence could have important advantages in terms of the quality of the surface processing, allow shorter source to target distances (again a more compact overall facility) and perhaps reduce levels of contamination leading to a cleaner and purer coating. A further advantage could be faster processing because of the ability to use higher energies and current densities.

Innovations and advantages of the offer

Beam divergence can be reduced by about a factor of 6 compared to conventional GIE.

Allows ion sources to be more compact.

Allows overall vacuum chamber to be smaller.

Be able to deliver the same overall current from a smaller source.

Can independently control the ion energy and current density.

Application

It is envisaged that this technology should be primarily applicable to broad beam ion sources with energies in the keV range but there could also be possibilities for very fine ion beams used for example for ion beam milling or implantation at much higher energies in the MeV range.

Space Heritage

Developed for electronic propulsion of satellites in space.

Broker comments

This technology is still in the development phase but due to the nature of the applications, this is not necessarily a disadvantage. This is because most of the applications themselves are at a development phase and so a long term collaborative project is probably the best approach.